An interventional study of Freeze-Dried Grape Powder and Plain Low-Fat Yogurt in Metabolic Dysfunction-Associated Steatotic Liver Disease, Overweight and Obesity & Overweight, sponsored by University Rovira i Virgili. Active, not recruiting at 1 site in Spain. Open to participants aged 30 Years to 70 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-21.
Sponsored by University Rovira i Virgili · Not applicable, Interventional, and Basic science
The goal of this randomized clinical trial is to learn whether consuming grapes during their natural season can help the body adapt to the shorter daylight hours of winter. The study includes men and women aged 30-70 years with either normal weight or overweight or obesity and metabolic dysfunction-associated steatotic liver disease (MASLD).
The main questions it aims to answer are:
Within each population group, researchers will compare participants consuming yogurt with freeze-dried grape powder with participants consuming the same yogurt without grape powder. Both groups will receive the same Mediterranean-style dietary guidance.
Participants will:
This study investigates the role of seasonal fruit consumption in human adaptation to changes in day length. Seasonal variations in daylight influence biological rhythms and metabolic regulation. Dietary signals may also contribute to this adaptation, although evidence from human intervention studies remains limited.
The scientific rationale is based on the xenohormesis hypothesis, which proposes that plant-derived compounds can convey information about the environmental conditions in which plants grow. Grape polyphenols may therefore act as seasonal signals that influence physiological responses in the individuals consuming them. Previous preclinical research has shown that the biological effects of grape polyphenols can depend on photoperiod and may involve biological clocks, metabolic pathways, gut microbiota, and epigenetic regulation.
This study evaluates this hypothesis in humans during the transition to the winter photoperiod. The intervention is scheduled during the local grape harvest season, with its completion aligned with the autumn clock change. Follow-up after discontinuation of grape supplementation will allow researchers to explore whether any observed responses persist during the subsequent seasonal transition.
The study includes two population cohorts representing different metabolic contexts: individuals with normal weight and individuals with overweight or obesity and metabolic dysfunction-associated steatotic liver disease (MASLD). Randomization to grape supplementation or control is performed within each cohort. A common Mediterranean-style dietary framework is used in both intervention groups.
The research combines molecular profiling with physiological and behavioral assessments to explore potential links between dietary seasonal signals and adaptation to winter. Biological samples are collected at synchronized assessment periods, while wrist-worn devices provide longitudinal information on sleep and activity under everyday living conditions.
The study is not double-blind because the control product does not contain a specifically formulated placebo. Whenever feasible, biological sample processing and analysis will be performed with researchers masked to intervention allocation.
3,767 studies on the registry are indexed under Overweight; 863 are open to participants now.
This study's enrollment of 46 is below the median of 73 across 3,263 interventional studies indexed under Overweight.
Browse Overweight studies →University Rovira i Virgili is the lead sponsor of 52 studies on the registry; 9 are open to participants now.
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Participants consume 16 g of freeze-dried grape powder daily, equivalent to approximately 80 g of fresh grapes, divided between two servings of plain, low-fat yogurt without added sugar, taken in the morning and afternoon for 3 weeks. Participants also receive Mediterranean-style dietary guidance. The intervention is followed by 2 weeks without grape supplementation.
Dietary Supplement: Freeze-Dried Grape Powder · Other: Plain Low-Fat Yogurt · Behavioral: Mediterranean-Style Dietary Guidance
Participants consume two servings of plain, low-fat yogurt without added sugar daily, taken in the morning and afternoon for 3 weeks, without freeze-dried grape powder. Participants receive the same Mediterranean-style dietary guidance as the experimental arm. The intervention is followed by a 2-week follow-up period.
Other: Plain Low-Fat Yogurt · Behavioral: Mediterranean-Style Dietary Guidance
Freeze-dried Cabernet Sauvignon grape powder administered orally at a total dose of 16 g/day, equivalent to approximately 80 g of fresh grapes. The daily dose is divided into two servings, mixed with plain, low-fat yogurt without added sugar and consumed in the morning and afternoon for 3 weeks during the local grape harvest season. This is followed by 2 weeks without grape supplementation.
Two daily servings of plain, low-fat yogurt without added sugar, consumed in the morning and afternoon for 3 weeks.
Both arms receive the same dietary guidance based on a Mediterranean dietary pattern.
Change in circulating plasma microRNA expression
Differential expression of circulating microRNAs in plasma, comparing changes from baseline between the grape supplementation and control arms at the end of the intervention and after follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in DNA methylation in promoter regions of selected genes
Changes in DNA methylation in the promoter regions of selected genes, measured by pyrosequencing after bisulfite treatment of DNA isolated from peripheral blood mononuclear cells (PBMCs). Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and after follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in serum metabolomic profile
Changes in the serum metabolomic profile assessed by proton nuclear magnetic resonance (1H-NMR). Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and after follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in gut microbiota diversity and composition
Changes in bacterial diversity and composition assessed by 16S ribosomal RNA gene sequencing of stool samples. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and after follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in body weight
Change in body weight, measured in kilograms, from baseline to the end of the intervention and follow-up, comparing the grape supplementation and control arms.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in body mass index
Change in body mass index (BMI), calculated as body weight in kilograms divided by height in meters squared (kg/m²), from baseline to the end of the intervention and follow-up, comparing the grape supplementation and control arms.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in waist circumference
Change in waist circumference, measured in centimeters, from baseline to the end of the intervention and follow-up, comparing the grape supplementation and control arms.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in body composition assessed by bioelectrical impedance
Changes in body composition assessed using a TANITA bioelectrical impedance device, comparing changes from baseline between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in systolic and diastolic blood pressure
Changes in resting systolic and diastolic blood pressure, measured in mmHg using two readings taken one minute apart. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in resting heart rate
Change in resting heart rate, measured in beats per minute, from baseline to the end of the intervention and follow-up, comparing the grape supplementation and control arms.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in handgrip strength
Change in handgrip strength assessed by handgrip dynamometry, comparing changes from baseline between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in gait speed over a 4-meter distance
Change in gait speed, measured in meters per second using a 4-meter walk test to assess functional performance. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in fasting blood glucose
Change in fasting blood glucose measured using standardized clinical laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in fasting insulin
Change in fasting insulin measured using standardized clinical laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in glycated hemoglobin (HbA1c)
Change in glycated hemoglobin (HbA1c) measured using standardized clinical laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5)
Change in blood creatinine
Change in blood creatinine measured using standardized clinical laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5)
Change in liver enzyme levels
Changes in blood liver enzyme levels measured using standardized clinical laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5)
Change in blood lipid profile
Changes in the blood lipid profile measured using standardized clinical laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5)
Change in prothrombin measurements
Changes in prothrombin measurements assessed using standardized clinical laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5)
Change in blood ferritin
Change in blood ferritin measured using standardized clinical laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in blood albumin
Change in blood albumin measured using standardized clinical laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5)
Change in platelet count
Change in blood platelet count measured using standardized clinical laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5)
Change in blood melatonin levels
Change in blood melatonin levels measured using standardized laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5)
Change in blood cortisol levels
Change in blood cortisol levels measured using standardized laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in blood testosterone levels
Change in blood testosterone levels measured using standardized laboratory methods. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in blood triiodothyronine (T3) levels
Change in blood triiodothyronine (T3) levels from baseline to the end of the intervention and follow-up, comparing the grape supplementation and control arms.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in blood thyroxine (T4) levels
Change in blood thyroxine (T4) levels from baseline to the end of the intervention and follow-up, comparing the grape supplementation and control arms.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in complete blood count parameters
Changes in complete blood count parameters from baseline to the end of the intervention and follow-up, comparing the grape supplementation and control arms.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Liver stiffness assessed by shear-wave elastography
Liver stiffness assessed by quantitative shear-wave ultrasound elastography in participants with overweight or obesity and MASLD.
Time frame: Baseline (week 0).
Change in Fibrosis-4 (FIB-4) index
Changes in the Fibrosis-4 (FIB-4) index, a non-invasive liver fibrosis score calculated from age, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and platelet count, in participants with overweight or obesity and MASLD. Changes from baseline will be compared between the grape supplementation and control arms.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Change in AST-to-platelet ratio index (APRI)
Changes in the AST-to-platelet ratio index (APRI), a non-invasive liver fibrosis score derived from blood AST levels and platelet count, in participants with overweight or obesity and MASLD. Changes from baseline will be compared between the grape supplementation and control arms.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Sleep-wake patterns assessed by a wrist-worn device
Sleep-wake patterns recorded longitudinally using a wrist-worn device during the intervention and follow-up periods, comparing the grape supplementation and control arms.
Time frame: Throughout the 3-week intervention and the subsequent 2-week follow-up (weeks 0-5).
Sleep patterns assessed by a sleep diary
Self-reported sleep patterns recorded using the American Academy of Sleep Medicine (AASM) sleep diary during the first week of intervention and the final week of follow-up, comparing the grape supplementation and control arms.
Time frame: First week of intervention (week 1) and final week of follow-up (week 5).
Sleep quality assessed by the Pittsburgh Sleep Quality Index (PSQI)
Self-reported sleep quality assessed using the Pittsburgh Sleep Quality Index (PSQI).
Time frame: Baseline (week 0).
Physical activity assessed by the International Physical Activity Questionnaire-Short Form
Self-reported physical activity assessed using the short form of the International Physical Activity Questionnaire (IPAQ-short).
Time frame: Baseline (week 0).
Change in Mediterranean diet adherence
Changes in adherence to the Mediterranean dietary pattern assessed using the Mediterranean diet adherence questionnaire specified in the protocol. Changes from baseline will be compared between the grape supplementation and control arms at the end of the intervention and follow-up.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Dietary intake assessed by a 48-hour dietary record
Dietary intake assessed using participant-completed 48-hour dietary records at baseline, the end of the intervention, and follow-up, comparing the grape supplementation and control arms.
Time frame: Baseline (week 0), end of intervention (week 3), and end of follow-up (week 5).
Occurrence of adverse events
Occurrence of adverse events recorded during the grape supplementation or control intervention and the subsequent follow-up period.
Time frame: Throughout the 3-week intervention and the subsequent 2-week follow-up (weeks 0-5).
Started Sep 2026 (actual). Primary completion is estimated for Nov 2026, 1 month after the start.
Of 1,356 non-industry interventional studies with no phase under Overweight, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 38. This study's planned 1 month is below that.
Counting every sponsor, half of 1,472 studies reached it within 17 months; a quarter within 7 and three quarters within 36.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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